linux/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c

/*
 * Copyright 2014 Advanced Micro Devices, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Christian König <[email protected]>
 */

/**
 * DOC: MMU Notifier
 *
 * For coherent userptr handling registers an MMU notifier to inform the driver
 * about updates on the page tables of a process.
 *
 * When somebody tries to invalidate the page tables we block the update until
 * all operations on the pages in question are completed, then those pages are
 * marked as accessed and also dirty if it wasn't a read only access.
 *
 * New command submissions using the userptrs in question are delayed until all
 * page table invalidation are completed and we once more see a coherent process
 * address space.
 */

#include <linux/firmware.h>
#include <linux/module.h>
#include <drm/drm.h>

#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
#include "amdgpu_hmm.h"

#define MAX_WALK_BYTE …

/**
 * amdgpu_hmm_invalidate_gfx - callback to notify about mm change
 *
 * @mni: the range (mm) is about to update
 * @range: details on the invalidation
 * @cur_seq: Value to pass to mmu_interval_set_seq()
 *
 * Block for operations on BOs to finish and mark pages as accessed and
 * potentially dirty.
 */
static bool amdgpu_hmm_invalidate_gfx(struct mmu_interval_notifier *mni,
				      const struct mmu_notifier_range *range,
				      unsigned long cur_seq)
{ … }

static const struct mmu_interval_notifier_ops amdgpu_hmm_gfx_ops = …;

/**
 * amdgpu_hmm_invalidate_hsa - callback to notify about mm change
 *
 * @mni: the range (mm) is about to update
 * @range: details on the invalidation
 * @cur_seq: Value to pass to mmu_interval_set_seq()
 *
 * We temporarily evict the BO attached to this range. This necessitates
 * evicting all user-mode queues of the process.
 */
static bool amdgpu_hmm_invalidate_hsa(struct mmu_interval_notifier *mni,
				      const struct mmu_notifier_range *range,
				      unsigned long cur_seq)
{ … }

static const struct mmu_interval_notifier_ops amdgpu_hmm_hsa_ops = …;

/**
 * amdgpu_hmm_register - register a BO for notifier updates
 *
 * @bo: amdgpu buffer object
 * @addr: userptr addr we should monitor
 *
 * Registers a mmu_notifier for the given BO at the specified address.
 * Returns 0 on success, -ERRNO if anything goes wrong.
 */
int amdgpu_hmm_register(struct amdgpu_bo *bo, unsigned long addr)
{ … }

/**
 * amdgpu_hmm_unregister - unregister a BO for notifier updates
 *
 * @bo: amdgpu buffer object
 *
 * Remove any registration of mmu notifier updates from the buffer object.
 */
void amdgpu_hmm_unregister(struct amdgpu_bo *bo)
{ … }

int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier,
			       uint64_t start, uint64_t npages, bool readonly,
			       void *owner, struct page **pages,
			       struct hmm_range **phmm_range)
{ … }

bool amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range)
{ … }